The Sun

Sun Facts Our sun accounts for 99.8% of ALL the mass in our solar system Average size star ( ~ 1.3 million Earths could fit inside the sun ) Estimated age 4.6 billion years old Light takes 8 minutes to reach Earth

The Sun’s Structure The sun does not have a solid surface (granules) It is a giant ball of glowing PLASMA Mostly Hydrogen and Helium Small amounts of other elements Has an atmosphere and an interior

The Sun’s Interior The sun’s interior consists of the Core Radiation Zone Convection Zone

The Core The core is where the suns energy is produced – it is the inner most layer of the sun Temperature 27,000,000 °F Hydrogen atoms join (fuse) together to form Helium Nuclear fusion can only occur under extremely high temperature and pressure

The Radiation Zone The middle layer of the sun’s interior Region of very tightly packed gas Energy is transferred here by electromagnetic radiation Takes energy about 100,000 years to move through

The Convection Zone Outermost layer of the sun’s interior Hot gases rise from bottom of this layer and move up – then cool and move back down Convection currents

The Sun’s Atmosphere Made up of three layers Photosphere Chromosphere The inner layer of the atmosphere (surface layer) Means “light” – it is the part of the sun we see ~ 300 miles thick 10,800 ° F Chromosphere “color sphere” - ~ 6000 miles thick Middle layer – 180,000 °F Corona The “crown” or outer most layer – 1,800,000 °F Extends millions of miles into space Gradually thins and changes into solar wind

The Sun’s Corona

Features on the Sun Sunspots Cool areas on the photosphere Show up as dark spots Number of sunspots vary – follows an 11 year cycle

Prominences A huge, reddish loop of gas that protrudes from the sun’s surface, linking parts of sunspot regions

Solar Flares An explosion of gas from the sun’s surface that occurs when the loops of sunspot regions suddenly connect

Solar Wind A stream of electrically charged particles that forms in the sun’s corona and flows out into space at high speed